The present invention relates to support tooling used for supporting metal parts while subjecting those parts to heat treatments such as annealing, brazing, shaping, etc.
Heat treatments of parts made of metal material, such as titanium or other materials, are performed at high temperatures that may exceed 1000° C. By way of example, with parts made of titanium, it is common practice during fabrication to subject a part to a so-called “anneal” heat treatment at temperatures at which titanium becomes soft. Under such circumstances, the titanium part deforms (creeps) merely under the effect of gravity, and it remains deformed after it has cooled. The part may also twist during reductions of temperature as a result of internal stresses being released.
Thus, very heavy single-piece metal supports, e.g. made of refractory steel, are generally used for supporting a part during heat treatment. Nevertheless, the use of such supports presents several drawbacks.
Firstly, such supports are usually very bulky and heavy. Consequently they reduce the loading capacity of the oven used for the heat treatments, while also being difficult to handle. They also present significant thermal inertia, which leads to large amounts of energy consumption in order to raise the tooling to high temperature, and they require long periods of time for cooling, thereby reducing the productivity of the installation. In addition, such large thermal inertia puts a limit on the temperature gradients needed for obtaining the desired microstructure. That type of support also presents a coefficient of thermal expansion that is high, usually different from that of the material of the part being treated, thus limiting its use to parts having geometrical shapes that are simple and making it necessary to provide for large amounts of reshaping by machining of the parts in order to ensure they end up with their intended geometrical configuration.
Finally, that type of support deforms during heat treatments as a result of repeated thermal shocks.